1.1 jmmv 1: [[!template id=project
2:
3: title="Add snapshots to tmpfs"
4:
5: contact="""
6: [tech-kern](mailto:tech-kern@NetBSD.org)
7: """
8:
9: category="filesystems"
1.2 ! jmmv 10: difficulty="medium"
1.1 jmmv 11:
12: description="""
13: Add memory-efficient snapshots to tmpfs. A snapshot is a view of the
14: filesystem, frozen at a particular point in time. The snapshotted filesystem is
15: not frozen, only the view is. That is, you can continue to
16: read/write/create/delete files in the snapshotted filesystem.
17:
18: The interface to snapshots may resemble the interface to null mounts, e.g.,
19: 'mount -t snapshot /var/db /db-snapshot' makes a snapshot of /var/db/ at
20: /db-snapshot/.
21:
22: You should exploit features of the virtual memory system like copy-on-write
23: memory pages to lazily make copies of files that appear both in a live tmpfs and
24: a snapshot. This will help conserve memory.
25: """
26: ]]